Quimby s



Patented Oct. I9, 1880.

Bit Stock.'

Q. s. BAGKUS.

ILPETEES. PHOTO LITHOGRAPH fcf@ f7@ @7m UNITED STATES PATENT OFFICE.

QUIMBY S. BAGKUS, OF NEW YORK, N. Y.

" BIT-STOCK.

SPECIFICATION forming part of Letters Patent No. 233,464, dated October 19, 1880.

Application filed .August 24, 1880.

To all whom t may concern Be it known that I, QUIMBY S. BACKUS, a citizen of the United States, residing at the city of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Bit-Stocks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to an improvement in that class of bit-braces in which the bit is held in place by its shank end entering a socket, while two movable jaws placed in slots formed in the sides of the socket clasp the bit just beyond the enlargement of the shank and are caused to grasp and hold it firmly by means of an internally-threaded conically-ended screwsleeve, which engages with a corresponding screw-thread upon the socket, rotation of this sleeve in one direction causing its conical end to force the jaws toward each other and thus grasp the bit, and when turned in the opposite way to release it and the invention consists in the construction of and means employed for retaining the jaws in place, as will be hereinafter' fully described.

In the drawings, Figure 1 shows a section of the sleeve, with a side view of the socket and one of the jaws. Fig. 2 is a section through the sleeve and socket, showing the jaws closed upon the shank of a bit; Fig. 3, a side view of the socket, showing the slots for holding the jaws and the hole through which the1 spring passes that connects their lower en s.

The letter A represents that portion of the bit-brace which forms the handle, and which may be constructed in any of the many wellknown ways now in use. Formed as a part of or securely attached to the part A is the enlarged cylindrical end or socket B, having a screw-thread cut or otherwise' formed upon its outer surface and its end bifurcated by means of a slot, C. This slot has a solid portion or partition, a, extending a part of the (No model.)

way from the bottom, and provided at its outer end with the angular recess b, which receives and forms a bearing for the shank end of the bit. This partition is also pierced with a hole, c, through which the coiled spring d connecting the ends of the jaws D D is passed. Ihese jaws have the double inclined or wedge outline shown in Fig. 2, the incline upon the outer surface being formed in two parts, one of which serves as a bearing for the conical inner surface of the sleeve, while the others give to the jaws such a form as enables them to pass easily upon opposite sides of the partition a, retaining sufficient freedom of movement within the slots, and removes from them all superfluous metal which would increase their weight and add strength at points where it was not needed. The inner side of these jaws D D is provided with a longitudinal groove or recess, in which the enlarged part of the bit-shank is received, as illustrated by the dotted lines in Fig. 2. They are also united to each other and to the socket B by the coiled spring d, which passes through the hole c in the partition a and forms the sole bond of union between the parts.

It will be observed that the jaws rest upon the salient point or projection c of the partition c in such a manner that the latter forms a fulcrum, upon which the jaws oscillate like a lever, the spring-connection between their inner ends tending to continually draw them together at that point, and consequently forcing their outer ends apart as far as the conical end of the sleeve E, which bears upon them, will allow, thus causing the jaws to respond readily to the movement of the sleeve when it is desired to open them to receive or release a bit.

I am aware that the slotted and screwthreaded socket, as well as the internally screw-threaded sleeve moving upon the socket and causing movable jaws to act in holding the bit in place, are old, also that springs have been used between the lower ends of the jaws; but I am not aware that a coiled spring passing through an orice in the partition tof the socket has ever been used as the sole connection of the jaws with each other and with the socket, or that the jaws have ever been ful- IOO crumed upon the salient points of said partisole union between the jaws and socket, as

tion, as hereinbefore described. specified. 1o

I therefore claim as my invention, and de- In testimony whereof I ax my signature sire to secure by Letters Patent, the following: in presence of two witnesses.

The bit-holdingjaws, formed as described, QUIMBY S. BAOKUS. in combination with the salient points cof the Witnesses: socket and coiled spring d, passing through ELDRED A. CARLEY,

hole c in partition a, said spring forming the JOHN G. CAMERON. 

